1. Field of the Invention
The subject invention is directed to an on-line interconnect system for connecting a terminal with an internet and is specifically directed to the method and apparatus for enabling PC workstations on a local area network (LAN) to access the TCP/IP protocol internet without alteration of the PC hardware configuration and without the need for communication with a LAN server provider having a TCP/IP protocol stack.
2. Discussion of the Prior Art
An internet is a collection of disparate physical computer networks which are interconnected to function as a coordinated unit. The Internet is the interconnected network which includes the Defense Advanced Projects Research Agency (DARPA), the National Science Foundation (NSF), the Department of Energy (DOE) and the National Aeronautics and Space Administration (NASA), as well as most other research institutions, colleges and universities, and recently, most large companies. The Internet operates entirely under the protocol TCP/IP. Computers which communicate over the Internet must either use TCP/IP protocols or a TCP/IP protocol service provider.
Over the years local area networks or LANs have evolved and developed with protocols which are much simpler and more efficient than TCP/IP. The protocols do not require individual address management, or accessory functionality such as name servers to maintain the order of the membership. They were specifically designed to utilize a minimum memory capacity. While such systems are very useful for the intended purpose of linking a plurality of workstations to a central processor and to each other, they did not anticipate or plan for the need or desirability to permit each individual workstation to independently communicate via the Internet.
Several prior art systems have been developed with the objective of permitting LAN workstations to communicate with the Internet utilizing the required TCP/IP protocol. Initially, a second protocol, TCP/IP was added to each PC's native LAN protocol or the LAN was converted to exclusive use of the TCP/IP protocol. IBM, Microsoft and Novell are examples of companies providing a second or conversion protocol. The difficulty with these solutions were the installation and management of TCP/IP stacks in the LAN PCs, more memory utilization for the protocol and a slowdown of normal LAN operation due to the inherent inefficiencies of TCP/Ip protocol when used as a LAN protocol.
These problems were reduced by introduction of a shared TCP/IP into an existing server, which eliminated the TCP/IP from the LAN workstations and permitted the LAN to operate in its native protocol. These solutions relied upon existing PC operating systems for the server, the TCP/IP for these systems housing the server and the LAN interface used by the server. Many such systems relied upon a special code or on start-up facilities to be installed in each LAN PC. Examples of such systems include Firefox and Internetware (for Novell NetWare servers), Ipswitch (OS/2) and Fel (Windows). All require a PC operating system to house the server and to provide access to the native LAN protocols. While such systems did eliminate the need to convert the LAN protocol and reduced the use of memory and the alteration of the LAN client PCs, each proved costly to install and maintain.
There have also been a number of recently issued patents which disclose systems for interconnection of various terminals across different networks by mapping or providing different protocol schemes, where the computers have different protocols or different communications architecture. For example, U.S. Pat. No. 5,353,283, issued to P. F. Tsuchiya, et al, on Oct. 4, 1994, discloses a method for use in a large communication internet with several interconnected networks having one or more interconnected nodes. Specifically, an algorithm is provided for writing a sequence of one or more identifiers suitable for use in indexing a forwarding table at each node in a special routing section of each packet to be transmitted via the internet, to provide a routing method adapted to achieve different routing criteria and styles to accommodate varying structures and architecture.
U.S. Pat. No. 5,355,365, issued to D. Bhat, et al, on Oct. 11, 1994, provides for a share modem resource to PCs connected through a LAN and to off network PCs.
Various other methods and apparatus have been developed to provide access to various internets from individual workstations of a LAN. However, to date, all of the systems available require at least a partial combination of expensive hardware additions to either the LAN in the form of a PC server or to each workstation of the LAN; substantial memory utilization; use of a protocol service provider and/or limited simultaneous access to the internet via the shared system, for example, one user at a time on a shared modem.
It is, therefore, desirable to provide an internet access system wherein each LAN workstation can simultaneously directly communicate with the internet without requiring substantial hardware modification or DOS memory utilization in existing LAN workstations or servers.